The unfolding of the measles, mumps and rubella (MMR) controversy reveals some of the key features of the cultural climate affecting matters of health and illness in contemporary society. A high level of anxiety around issues of health is reflected in a heightened sense of individual vulnerability to environmental dangers (such as atmospheric pollution, electromagnetic fields, bioterrorism) and in a general aversion to risk, particularly in relation to children. This mood has proved responsive to views sceptical, if not hostile, towards science and medicine and associated professionals, particularly in the sphere of immunization. The result is that uptake of MMR vaccination in the UK has fallen, from a peak of 92% in the mid-1990s to a national level of 82% in 2003 (at the age of two); in London uptake is now less than 75%-much less in some areas-causing a significant risk of outbreaks of measles. In the USA too, the proportion of parents opting out of regulations requiring immunization as a condition of school entry has increased significantly in some areas, though these controversies appear to have had little impact so far in continental Europe.